Machine for joining together mutually crossing rods

Abstract

A machine for tying together mutually crossing rods with the aid of wire-ties includes a device 8, 9 having a curved wire-guide surface which is intended to be positioned so that it will surround a rod intersection point on three sides of the mutually crossing rods 6, 7. The machine also includes a mechanism 18-20 for feeding at least one wire to the device, so that the wire will be bent by the guide surfaces into a wire-stirrup which surrounds the intersection point on three sides, and a rotatable twisting head by means of which the free legs of the stirrup are twisted together on the fourth side of the intersection point. The machine also includes a feed tube 18 for feeding severed, straight wire-sections 16 of predetermined lengths, and the lower end of the feed tube is located above an opening in the twisting head positioned in line with a part of the guide surface. Mounted for axial movement in the tube is a device which functions to press wire-sections introduced into the tube in a downward direction and displace the wire-sections along the guide surface, to form a wire-stirrup.

I claim: 
     
       1. A machine for joining together mutually crossing rods with the aid of wires, particularly for tying reinforcement rods, said machine including a device (8, 9) having a curved wire-guide surface which is intended to be positioned so that said surface will substantially embrace the intersection point of two rods (6, 7) on three sides thereof, means (18-20) for feeding at least one wire to said device, so that the wire is bent by said guide surface to the shape of a wire-stirrup surrounding said intersection point on three sides thereof, and a rotatable twisting head (21, 22) which functions to twist the free legs of the stirrup on the fourth side of said intersection point, wherein the machine further includes a feed tube (18) for severed, straight wire-sections (16) of predetermined lengths, the lower end of said tube being located above an opening (23) in the twisting head (21, 22) in line with a part of said guide surface; and further comprising means (20) moveable in the tube (18) for coaction with a wire-section (16) inserted therein, such as to press down and displace said wire-section along said guide surface and forming of said wire-section to a stirrup-like shape, wherein the device provided with a curved guide surface includes two curved jaws (8, 9) which are pivotal towards one another; the inner surfaces of the jaws are provided with open wire-section guide grooves, the groove in the curved inner surface of the jaw (8) which first meets the forward end of the wire-section (16) has a substantially circular curvature; and the curvature of the groove in the second jaw (9) has a radius of curvature which is greater than the radius of curvature of the groove in the first jaw. 
     
     
       2. A machine according to claim 1, wherein the means arranged for movement in the tube (18) has the form of a plunger (20) which acts on the upper end of respective wire-sections (16). 
     
     
       3. A machine for joining together mutually crossing rods with the aid of wires, particularly for tying reinforcement rods, said machine including a device (8, 9) having a curved wire-guide surface which is intended to be positioned so that said surface will substantially embrace the intersection point of two rods (6, 7) on three sides thereof, means (18-20) for feeding at least one wire to said device, so that the wire is bent by said guide surface to the shape of a wire-stirrup surrounding said intersection point on three sides thereof, and a rotatable twisting head (21, 22) which functions to twist the free legs of the stirrup on the fourth side of said intersection point, wherein the machine further includes a feed tube (18) for severed, straight wire-sections (16) of predetermined lengths, the lower end of said tube being located above an opening (23) in the twisting head (21, 22) in line with a part of said guide surface; and further comprising means (20) moveable in the tube (18) for coaction with a wire-section (16) inserted therein, such as to press down and displace said wire-section along said guide surface and forming of said wire-section to a stirrup-like shape, wherein the device provided with a curved guide surface includes two curved jaws (8, 9) which are pivotal towards one another; the inner surfaces of the jaws are provided with open wire-section guide grooves, and the jaws (8, 9) are journalled so that said jaws will move axially when pivoting relative to one another. 
     
     
       4. A machine according to claim 3, wherein the position of the jaw attachment means on the machine can be adjusted axially in a manner to adapt the machine to rods (6, 7) of mutually different diameters. 
     
     
       5. A machine for joining together mutually crossing rods with the aid of wires, particularly for tying reinforcement rods, said machine including a device (8, 9) having a curved wire-guide surface which is intended to be positioned so that said surface will substantially embrace the intersection point of two rods (6, 7) on three sides thereof, means (18-20) for feeding at least one wire to said device, so that said wire is bent by said guide surface to the shape of a wire-stirrup surrounding said intersection point on three sides thereof, and a rotatable twisting head (21, 22) which functions to twist the free legs of the stirrup on the fourth side of said intersection point, wherein the machine further includes a feed tube (18) for severed, straight wire-sections (16) of predetermined lengths, the lower end of said tube being located above an opening (23) in the twisting head (21, 22) in line with a part of said guide surface; and further comprising means (20) moveable in the tube (18) for coaction with a wire-section (16) inserted therein, such as to press down and displace said wire-section along said guide surface and forming of said wire-section to a stirrup-like shape, wherein the twisting head comprises two rotatably, disc-shaped bodies (21, 22), each provided with a pair of openings (23, 24) for receiving the legs of a wire-stirrup; and the discs are mounted for limited movement relative to one another such as to clamp the legs of the wire-stirrup firmly between the discs prior to a twisting operation. 
     
     
       6. A machine according to claim 5, wherein the openings (24) in the disc-shaped bodies intended for receiving the forward end of the wire (16) bent to stirrup form have an elongated shape in the radial direction. 
     
     
       7. A machine for joining together mutually crossing rods with the aid of wires, particularly for tying reinforcement rods, said machine including a device (8, 9) having a curved wire-guide surface which is intended to be positioned so that said surface will substantially embrace the intersection point of two rods (6, 7) on three sides thereof, means (18-20) for feeding at least one wire to said device, so that the wire is bent by said guide surface to the shape of a wire-stirrup surrounding said intersection point on three sides thereof, and a rotatable twisting head (21, 22) which functions to twist the free legs of the stirrup on the fourth side of said intersections point, wherein the machine further includes a feed tube (18) for severed, straight wire-sections (16) of predetermined lengths, the lower end of said tube being located above an opening (23) in the twisting head (21, 22) in line with a part of said guide surface; and further comprising means (20) moveable in the tube (18) for coaction with a wire-section (16) inserted therein, such as to press down and displace said wire-section along said guide surface and forming of said wire-section to a stirrup-like shape, wherein the twisting head (21, 22) is mounted for movement axially in a sleeve (37) surrounding said head, and the lower end of the sleeve is intended to rest on the rods (6, 7) to be joined together. 
     
     
       8. A machine according to claim 7, wherein the bottom edge of the sleeve (37) is provided with two pairs of diametrically opposed recesses (30, 40) which are intended to fit on the top of the rods (6, 7) to be jointed together and therewith correctly position the machine. 
     
     
       9. A machine for joining together mutually crossing rods with the aid of wires, particularly for tying reinforcement rods, said machine including a device (8, 9) having a curved wire-guide surface which is intended to be positioned so that said surface will substantially embrace the intersection point of two rods (6, 7) on three sides thereof, means (18-20) for feeding at least one wire to said device, so that the wire is bent by said guide surface to the shape of a wire-stirrup surrounding said intersection point on three sides thereof, and a rotatable twisting head (21, 22) which functions to twist the free legs of the stirrup on the fourth side of said intersection point, characterized in that the device provided with a curved guide surface includes two curved jaws (8, 9) which are pivotal towards one another; that the inner surfaces of the jaw are provided with open wire guide grooves; that the groove in the curved inner surface of the jaw (8) which first meets the forward end of the wire (16) has a substantially circular curvature; and in that the curvature of the groove in the second jaw (9) has a radius of curvature which is greater than the radius of curvature of the groove in the first jaw.